1998 Discovery I SE7 rebuild

[sunshineking]

Bought this 1998 Disco SE7 about 2 months ago with 118k on board and a blown head gasket.
This car runs hot and the only way to keep it from overheating when you drive it is to turn the heat on to max inside.Oil leaks from the front cover , side of the cyl heads and oil pan so decided to do a head gasket job.
I have a few questions for the guys who have done this b4..
I called a local machine shop to have the heads resurfaced and valve job done, picked up 16 valve seals from local dealer but 8 are in green and the other 8 in blue color..they all look the same to me
Q1---: are the valve seals the same for the exhaust and intake valves?

Q2---: In the manual is specified the use of special tool LRT-12-090 for the installation of front cover,can I do it without this tool? if not where can I get one?

Q3---:front cover gasket is supposed to be coated with hylosil sealant b4 installation according to the manual..is this correct when installing a new gasket?

Q4---:For oil pan gasket use hylosil sealant or normal oil pan gasket like the one available at roverpartsdotcom?

any help and suggestion will be appreciated

 

[joey]

I will look into the questions you have, but just an FYI you have attempted to repost this 4 times now... the server will keep blocking the reposts. Please try to keep you questions on this in this post and not repost the same info over.

Thanks,

 

[sunshineking]

thanks a lot..Sorry about multiple postings..

 

[joey]

Q1 - I can not find any info that says they are different. I am sure if someone elses knows more they will speak up.

Q2 - I am sure you can... per the book it is just used to rotate the shaft to align the key.

Q3 - you can install it without coating it with your preferred gasket sealant, but it will leak.

Q4 - Gasket sealant (i.e. gasket in a tube)

Download the repair manual and it will help a lot.

http://www.google.com/url?sa=t&ct=res&cd=2&url=http%3A%2F%2Fwww.landrover.ee%2Fest%2Ffiles%2Fmanuals%2Fengine%2FV8overhaulManual.pdf&ei=XvJmR4PYN47MggLwrdH6Dg&usg=AFQjCNGP2jMVgrm_PUKvV3K715LryHoRGg&sig2=wL3NKHPrg1_Aj-y7VmQLwQ

 

[Chongo]

1998 Discovery I SE7 rebuild

Bought this 1998 Disco SE7 about 2 months ago with 118k on board and a blown head gasket.
This car runs hot and the only way to keep it from overheating when you drive it is to turn the heat on to max inside.Oil leaks from the front cover , side of the cyl heads and oil pan so decided to do a head gasket job.
I have a few questions for the guys who have done this b4..
I called a local machine shop to have the heads resurfaced and valve job done, picked up 16 valve seals from local dealer but 8 are in green and the other 8 in blue color..they all look the same to me
Q1---: are the valve seals the same for the exhaust and intake valves?

Q2---: In the manual is specified the use of special tool LRT-12-090 for the installation of front cover,can I do it without this tool? if not where can I get one?

Q3---:front cover gasket is supposed to be coated with hylosil sealant b4 installation according to the manual..is this correct when installing a new gasket?

Q4---:For oil pan gasket use hylosil sealant or normal oil pan gasket like the one available at roverpartsdotcom?

any help and suggestion will be appreciated



Hello Sunshineking:

Q1 : The reason for the seals on the intake valves is so the intake pressure differentials, ( vacuum ) doesn’t allow engine oils pass the valve guides and inter into the intake. This is required on the intake valves only. I’ve seen and heard of people installing seals on the exhaust valve stems, why they do it, I don’t know, It is not necessary, or even needed. The pressure differentials on exhaust valves work on the valve guides in the opposite direction than that of the intake. You have more pressure in the exhaust system than you do in the crankcase due to the crank case placed under vacuum by the crankcase vent system leading to the intake plenum, this makes the oil flow back into the crankcase areas rather than into the exhaust. On my engine rebuild I left off the seals on the exhaust valves, as I have any engine I have ever done. It may hurt the exhaust valves by installing the seals on them, and not allowing some lubrication in the valve guide areas. This causes sticking exhaust valves sometimes, especially when there are tight tolerances, and high thermals. Placing seals on the exhaust valve stems is placing this seal in a very high thermal environment, it usually ends up as flexible as uncooked spaghetti, and defeats the purpose anyway. You only need 8 seals on the intake valve stems.


Q2 : I agree with Joey. But placing the bolt back into the crank spaced by extra temporary washers, and turning it with a wrench will save you from buying one.
I will add that it is very very important to align the housing to center the eccentric oil gear in the timing cover. This is done by turning the crankshaft several times before tightening the bolts that hold down the timing cover to the block. This centers the eccentric oil pump gear in the timing cover. Not following this procedure could result in timing cover and oil pump failure.


Q3 : I have no experience with Hylosil. I bought one tube of permatex Hylomar and never bought it again………….

On paper gaskets, one of my favorites is Permatex spray a gasket item #80064
Spray it on let it dry and get tacky, install, only lightly tightening the fasteners, and then after a few hours of drying, torque to specifications, watching to see if the gasket starts to squeeze out, if so allow more drying time. One helpful hint with this stuff is too much is not a good idea, just put on a light to med light coat. Comes in a 4.75 oz can, contents are red.

Q4 : For the pan gasket I used Permatex ultra gray in only 4 little areas. 2 where the timing cover joins the block, and the other 2 at the rear main cap.
The trick to using silicone sealants, is to clean the surface with lacquer Thinner, Methyl ethyl ketones or some alcohols that totally dry the surface free of any oils, before applying silicone sealants. Of course I’m using the one piece neoprene gasket. If it is not available for your year, use the Permatex spray adhesive on the cork, it works well.

Some old posts you might want to review………..



http://www.landroverworld.org/forums/member.php?u=7487


http://www.landroverworld.org/forums/showthread.php?t=11386


http://www.landroverworld.org/forums/showthread.php?t=11338


http://www.landroverworld.org/forums/showthread.php?t=11338


http://www.landroverworld.org/forums/showthread.php?t=11436


I hope this helps.......Chongo ..............

 

[joey]

Chongo... I have never heard of not using the seal on the exhaust valves, but what you say makes sense, I will have to try that on my next rebuild.

 

[Chongo]

Exhaust valve seals.

Chongo... I have never heard of not using the seal on the exhaust valves, but what you say makes sense, I will have to try that on my next rebuild.


I knew this post would probably shake a few people up but there is always a higher pressure on the exhaust side than in the crankcase areas. And oil will always be drawn to the lower pressure side. I’ve never had a high mileage engine that I tore down that had soft pliable exhaust seals. They were all hard and brittle, like uncooked spaghetti. And you can’t convince me that they seal in this condition. Once a seal looses it’s elasticity, it no longer seals.

I learned about this through several people, Chris Scercevic who was a great race engine builder in ventura Ca., Keith Black who’s shop is just a few miles away in San Fernando Valley and who needs no introduction, Ventura and Moorpark College engine departments , Mike Kodenko Race engine builder in Santa paula. Chevrolet, VW and Ford even stopped using them in some engines on the exhaust valves. Chevrolet also installs rotators on the exhaust valves and has no clearance for exhaust seals.
A lot of engine rebuild kits only come with enough to do just the intakes, especially VW.

This doesn’t mean you can’t put them on the exhaust valves, by all means, a person needs to do what they want to do, and I’m not here to stop them. And there is a lot of manufacturers and engine rebuilders who still install them on the exhaust valves. Why? Old school vs new school maybe ?

Some people have argued that the oil will burn in between the exhaust stem and valve guide, and cause the valve to stick. Others argue that a little oil in between the guide and exhaust valve helps lube and free things up. Others say it doesn’t really get in there anyway, so why worry if you put them on or not?

All I can say is that I have never experienced that it helps nor hurts the operation of the exhaust valves. Most air cooled engines don’t use them, So why put it in? It’s up to you.

The neat thing about it, it’s your engine you are rebuilding, and you get to decide how you want to do it, and if your successful, you get bragging rights…………………..


As always good luck and best wishes... Chongo...........

 

[joey]

Great info Chongo....